The present invention relates to an effector apparatus integrated into an audio amplifier such as a karaoke amplifier which is used by many and unspecified users.
In a specific use of the amplifier such as karaoke amusement, various effects including an echo and a sound field are imparted to an audio signal such as a musical sound signal which is amplified by the amplifier. In the karaoke amusement, the various effects are applied to the audio signal in order to improve atmosphere of the performance and situation.
Referring to FIG. 7, a conventional echo effector is briefly described. The echo effector has a front operation panel which contains three dials 11, 12 and 13 for adjusting a delay time, a repeat and an echo level, respectively. The echo effector imparts an echo to an inputted audio signal according to these parameters of the delay time, the repeat and the echo level. Such an echo effector is integrated into the karaoke amplifier or the like. However, these parameters are not independent from each other, but are mutually related to each other. Therefore, an adjustment of one parameter affects values of the remaining parameters. For example, the value of the echo level is unwantedly varied when either of the delay time and the repeat is adjusted. Therefore, it would be difficult to freely set a desired value of the echo level. If such an echo effector is owned by a specified user, a total adjustment may be conducted by trial and error method. However, the karaoke amplifier is generally used by many and unspecified persons. It is practically difficult for each person to set a desired echo effect according to his/her preference.
In another point of view, a range of each parameter is preset by factory. Therefor, a user can only operate the dials 11, 12 and 13 within the fixed range. The user (could not adjust, a value of each parameter beyond the preset range. For example, if the range of the delay time is preset from 0 msec to 100 msec, the user could not set the value of the delay time to 150 msec out of the range. Generally, the karaoke amplifier is used by many and unspecified persons having diverse and different preferences over a wide range. Therefore the factory-set range could not cover such an actual wide range.
In a separate point of view, a sound field effector is integrated into the karaoke amplifier in addition to the echo effector. The sound field effector is operated by a control program to create a typical sound field. However, the karaoke amplifier is installed in various types of rooms. The program is edited by a user to modify the sound field to conform with situation of the room. This edit work may be conducted initially at the installation. However, if the amplifier is replaced, the edit work must be done again. Even worse, if the sound field effector stores a plurality of control programs corresponding to different types of sound fields, such an edit work must be carried out for each program.